Built in Rechargeable lithium Battery allows 140 hours of use (charging cable included) * Compatible with Android, iOS, and Windows. Features function keys including Volume, music control, brightness control * Built in auto sleep system ensures you get the maximum use out of each charge * Slim Ergonomic Design Great for enjoyable use with PC computers, iPads and other tablets. Keyboard measures 5.25"x10.25" * Choose baclight color from 7 options as well as 2 brightness levels.